I have a stay booked here for August with my wife and 15 year old son. It's our first trip to Japan. We have the 50sq meter King room. The hotel told me they can put an extra bed in the room for no extra charge. Does anyone have experience with doing this at this property? I'm trying to get a sense of the comfort level/bed quality of the extra bed. As in, will this be a proper bed or something less than that?